IC Package Heat Sink Trenches to Contain TIM and Adhesive

Solution Overview

Problem

Existing integrated circuit packages with heat sinks face issues of thermal interface material (TIM) spreading and mixing with adhesive materials, leading to chemical incompatibility and reduced heat dissipation efficiency due to increased thermal resistance.

Innovation Solution

A new package structure is introduced, featuring a support substrate with a coating that includes a first trench surrounding the electronic chip, preventing TIM from spreading and mixing with adhesive materials, and a second trench for containing adhesive material, allowing for better control of TIM thickness and improved heat dissipation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pressure is reduced when mounting the heat sink to prevent TIM spreading, then chemical incompatibility risk is reduced, but thermal resistance increases due to thicker TIM layer

Engineering Contradiction:

Improvechemical compatibilityVSAvoidthermal resistance

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The coating is segmented into functional zones using trenches: a first trench surrounds the chip to contain TIM, while a second trench contains adhesive material. This spatial segmentation prevents mixing of TIM and adhesive regardless of mounting pressure, resolving the contradiction between preventing spreading and maintaining thin TIM layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trenches act as intermediary barriers between the TIM and adhesive material. By introducing these intermediate structures, the patent prevents direct contact between TIM and adhesive, allowing independent optimization of both materials without chemical incompatibility concerns.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If pressure is increased when mounting the heat sink to reduce TIM layer thickness, then thermal resistance decreases, but TIM spreads and mixes with adhesive material causing chemical incompatibility

Engineering Contradiction:

Improvethermal resistanceVSAvoidchemical compatibility

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The coating is segmented into functional zones using trenches: a first trench surrounds the chip to contain TIM, while a second trench contains adhesive material. This spatial segmentation prevents mixing of TIM and adhesive regardless of mounting pressure, resolving the contradiction between preventing spreading and maintaining thin TIM layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trenches are formed in the coating before mounting the heat sink, establishing physical barriers in advance. This preliminary action ensures that even if TIM spreads during mounting, it will be contained by the trenches and cannot reach the adhesive material, allowing high pressure to be applied safely.

Inventive Principle:

Principle #10Preliminary action

3Temperature

If TIM layer thickness is reduced to improve heat dissipation, then thermal resistance decreases, but TIM is more likely to spread and mix with adhesive material

Engineering Contradiction:

Improvethermal resistanceVSAvoidchemical compatibility

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The coating is segmented into functional zones using trenches: a first trench surrounds the chip to contain TIM, while a second trench contains adhesive material. This spatial segmentation prevents mixing of TIM and adhesive regardless of mounting pressure, resolving the contradiction between preventing spreading and maintaining thin TIM layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The trenches act as intermediary barriers between the TIM and adhesive material. By introducing these intermediate structures, the patent prevents direct contact between TIM and adhesive, allowing independent optimization of both materials without chemical incompatibility concerns.

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The proposed solution effectively reduces the thermal resistance of the TIM layer by approximately 33% compared to prior art, enhancing heat dissipation efficiency while preventing chemical incompatibility issues.

Implementation Method 1

a thermal interface material layer (70) located between the electronic chip (50) and the heat sink (80)

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

enhancing heat dissipation efficiency while preventing chemical incompatibility issues

Methodology Applied

Scientific EffectHeat dissipation: Heat Sink

Data Source

PatentUS12278155B2Integrated circuit package with heat sink and manufacturing method thereof

Publication Date: 2025.04.15 STMICROELECTRONICS (GRENOBLE 2) SAS

AI summary

A support substrate supports an electronic chip. An encapsulation coating on the support substrate coats the electronic chip. The encapsulation coating includes a trench surrounding the electronic chip. A heat sink is mounted to the encapsulation coating above the electronic chip. The heat sink is fixed to the encapsulation coating by an adhesive material and a thermal interface material layer is present between the electronic chip and the heat sink. The trench is positioned between the thermal interface material layer and the adhesive material.